Computations of nearshore wave transformation using finite-volume method

The accurate computation of nearshore wave transformation is a major aspect of the design of coastal structures and the prediction of nearshore currents and shoreline changes. This paper adopts the finite-volume method with adequate numerical algorithms for computing the wave transformation based on the hyperbolic time-dependent mild-slope equations involving wave breaking. Both the predictor–corrector scheme and the time-staggered leapfrog scheme were employed to discretize the governing equations; their results were first compared to the analytic solution for wave shoaling over a sloped beach to ascertain their accuracy. Results presented here using the time-staggered leapfrog scheme showed in better agreement with the experimental results. The numerical predictions for wave transmission over an elliptic shoal are then conducted and compared with the other models, from which the results show that the present model is in better agreement with the experimental results than the other numerical models. The successful simulations are also shown by practical examples including the waves around an offshore breakwater and around two offshore breakwaters with tombolo topography.

▸ This paper adopts the finite-volume method to compute nearshore wave transformation. ▸ A time-staggered leapfrog scheme is adopted, rather than a multiple numerical scheme. ▸ Results showed in better agreement with the experiments than previous models. ▸ The successful simulations are also shown by practical examples.